Book Image

KVM Virtualization Cookbook

Book Image

KVM Virtualization Cookbook

Overview of this book

Virtualization technologies such as KVM allow for better control over the available server resources, by deploying multiple virtual instances on the same physical host, or clusters of compute resources. With KVM it is possible to run various workloads in isolation with the hypervisor layer providing better tenant isolation and higher degree of security. This book will provide a deep dive into deploying KVM virtual machines using qemu and libvirt and will demonstrate practical examples on how to run, scale, monitor, migrate and backup such instances. You will also discover real production ready recipes on deploying KVM instances with OpenStack and how to programatically manage the life cycle of KVM virtual machines using Python. You will learn numerous tips and techniques which will help you deploy & plan the KVM infrastructure. Next, you will be introduced to the working of libvirt libraries and the iPython development environment. Finally, you will be able to tune your Linux kernel for high throughput and better performance. By the end of this book, you will gain all the knowledge needed to be an expert in working with the KVM virtualization infrastructure.
Table of Contents (15 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

The Linux bridge


The Linux bridge is a software layer 2 device that provides some of the functionality of a physical bridge device. It can forward frames between KVM guests, the host OS, and virtual machines running on other servers, or networks. The Linux bridge consists of two components--a userspace administration tool that we are going to use in this recipe and a kernel module that performs all the work of connecting multiple Ethernet segments together. Each software bridge we create can have a number of ports attached to it, where network traffic is forwarded to and from. When creating KVM instances, we can attach the virtual interfaces that are associated with them to the bridge, which is similar to plugging a network cable from a physical server's NIC to a bridge/switch device. Being a layer 2 device, the Linux bridge works with MAC addresses and maintains a kernel structure to keep track of ports and associated MAC addresses in the form of a Content Addressable Memory (CAM) table...